291. Lee WA, Brown MP, Martin TD, et al. Early results after staged hybrid repair of thoracoabdominal

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292. Patel R, Conrad MF, Paruchuri V, et al. Thoracoabdominal aneurysm repair: hybrid versus open

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293. Reddy DJ, Shepard A, Evans JR, et al. Management of infected aortoiliac aneurysms. Arch Surg

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294. Ellenby MI, Ernst CB. Surgical treatment of infected abdominal aortic aneurysms. In: Ernst CB,

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295. Brown SL, Busuttil RW, Baker JD, et al. Bacteriologic and surgical determinants of survival in

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299. Kan C, Lee H, Yang Y. Outcome after endovascular stent graft treatment for mycotic aortic

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301. Taheri SA, Kulaylat MN, Grippi J, et al. Surgical treatment of primary aortoduodenal fistula. Ann

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302. Debonnaire P, Van Rillaer O, Arts J, et al. Primary aorto enteric fistula: report of 18 Belgian cases

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304. French JR, Simring DV, Merrett N, et al. Aorto-enteric fistula following endoluminal abdominal

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horseshoe kidney. Cardiovasc Intervent Radiol 2004;27:632–636.

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Circulation 2006; 113:e463–e654.

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contemporary experience. Ann Surg 1996;223:555,65; discussion 565–567.

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mesenteric occlusive disease: early results and late outcomes. J Vasc Surg 1999;29:821,31;

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aortic aneurysm repair, renal artery bypass, and mesenteric revascularization. J Vasc Surg

2001;34:54–61.

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320. Sarac TP, Altinel O, Kashyap V, et al. Endovascular treatment of stenotic and occluded visceral

arteries for chronic mesenteric ischemia. J Vasc Surg 2008;47:485–491.

321. Silva JA, White CJ, Collins TJ, et al. Endovascular therapy for chronic mesenteric ischemia. J Am

Coll Cardiol 2006;47:944–950.

322. Oderich GS, Erdoes LS, Lesar C, et al. Comparison of covered stents versus bare metal stents for

treatment of chronic atherosclerotic mesenteric arterial disease. J Vasc Surg 2013;58:1316–1323.

323. Tollefson DF, Ernst CB. Natural history of atherosclerotic renal artery stenosis associated with

aortic disease. J Vasc Surg 1991;14:327–331.

324. Zierler RE, Bergelin RO, Isaacson JA, et al. Natural history of atherosclerotic renal artery stenosis:

a prospective study with duplex ultrasonography. J Vasc Surg 1994;19:250,7; discussion 257–258.

325. Williamson WK, Abou-Zamzam AM Jr, Moneta GL, et al. Prophylactic repair of renal artery

stenosis is not justified in patients who require infrarenal aortic reconstruction. J Vasc Surg

1998;28:14,20; discussion 20–22.

326. Thomas JH, Blake K, Pierce GE, et al. The clinical course of asymptomatic mesenteric arterial

stenosis. J Vasc Surg 1998;27:840–844.

327. Swanson RJ, Littooy FN, Hunt TK, et al. Laparotomy as a precipitating factor in the rupture of

intra-abdominal aneurysms. Arch Surg 1980;115:299–304.

328. Szilagyi DE, Elliott JP, Berguer R. Coincidental malignancy and abdominal aortic aneurysm.

Problems of management. Arch Surg 1967;95:402–412.

329. String ST. Management of concurrent intra-abdominal disease and abdominal aortic aneurysms. In:

Ernst CB, Stanley JC, eds. Current Therapy in Vascular Surgery. St. Louis, MO: Mosby; 1995:235.

330. Ochsner JL, Cooley DA, De Bakey ME. Associated intra-abdominal lesions encountered during

resection of aortic aneurysms: surgical considerations. Dis Colon Rectum 1960;3:485–490.

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Chapter 97

Lower Extremity Aneurysms

Amy B. Reed

Key Points

1 Femoral and popliteal aneurysms are often incidental findings on routine physical examination, but

are potentially limb threatening and frequently associated with life-threatening abdominal aortic

aneurysms.

2 Femoral artery aneurysms are the most common peripheral aneurysm if both true and false

aneurysms are considered together.

3 Anastomotic aneurysms result from a disrupted suture line between a graft and the host artery.

4 Pseudoaneurysms after percutaneous intervention result from failed hemostasis.

5 Popliteal artery aneurysms often develop limb-threatening complications if not treated electively.

6 Thrombolytic therapy is a useful adjuvant in patients presenting with acute limb ischemia secondary

to occlusion of a popliteal artery aneurysm and the outflow arteries.

PERIPHERAL ANEURYSMS

1 Popliteal artery aneurysms are the most frequently encountered peripheral aneurysm. Their

significance comes from their potential for limb-threatening complications, rather than rupture, and

their association with life-threatening abdominal aortic aneurysms. True femoral artery aneurysms are

rare, with iatrogenic and anastomotic pseudoaneurysms being more common.

Incidence

While the exact incidence of femoral and popliteal aneurysms is difficult to determine, the number

being recognized is increasing. An aging population, increased arterial trauma, more common use of

invasive therapies for vascular disease, and increased use of imaging modalities all contribute to the rise

in number of peripheral aneurysms being diagnosed. In a screening study of men between the ages of

65 and 74 years, abdominal aortic aneurysms were identified in 4.9% of patients.1 In patients with

abdominal aortic aneurysms, 6.8% had femoral artery aneurysms and 9.6% had popliteal artery

aneurysms.2 Screening of men between the ages of 65 and 80 years identified popliteal artery

aneurysms in 1%.3

An increasing number of false aneurysms – “pseudoaneurysms” – are occurring coincident with the

increased use of catheter-based diagnostic and therapeutic interventions in addition to lower extremity

bypass surgery. Pseudoaneurysms can be iatrogenic, infectious, or traumatic in nature and are identified

by their lack of involvement of all three vessel wall layers as is typically seen in true aneurysms. The

incidence of pseudoaneurysm after diagnostic procedures is approximately 0.3% – slightly higher at

1.5% after therapeutic procedures, in general due to use of larger sheaths.4 False aneurysms can also

arise from trauma during surgery, such as orthopedic procedures. Femoral pseudoaneurysms develop

after 0.08% of total hip arthroplasties, and popliteal aneurysms arise following 0.17% of total knee

arthroplasties.5

Degenerative (often called atherosclerotic) femoral and popliteal artery aneurysms are encountered

far more frequently in men than women. The male to female ratio in patients with femoral and

popliteal aneurysms is about 30:1.6–8 This predilection for men is markedly different from aortic

aneurysms where male to female patient ratio is approximately 4:1.2

Pathogenesis

The cause of femoral and popliteal aneurysms has changed significantly since they were first recognized

centuries ago. Once primarily mycotic or syphilitic in origin, most true aneurysms in the 21st century

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have a degenerative cause commonly called atherosclerotic aneurysms, whereas false aneurysms usually

follow surgery or trauma. True tibial artery aneurysms are rare.

The cause of degenerative aneurysms of the femoral and popliteal vessels is not clear. One factor

believed to contribute to aneurysm formation is turbulent flow beyond a relative stenosis resulting in

poststenotic dilatation beyond the inguinal ligament at the groin or beyond the tendinous hiatus of the

adductor magnus or the arcuate popliteal ligament and the heads of the gastrocnemius muscle at the

popliteal level. Arterial wall fatigue resulting from vibration and turbulence proximal to a major

branching or caused by stress during hip and knee flexion may also contribute to aneurysm formation.

The frequent occurrence of multiple peripheral aneurysms in the same patient suggests a systemic

abnormality in the arterial wall, which promotes aneurysmal degeneration at locations where

hemodynamic or mechanical factors put unusual stress on the arterial wall. The multiple factors that

contribute to aneurysmal degeneration and are felt to contribute to degenerative femoral and popliteal

aneurysms, as well as aortic aneurysms. The presence of an inflammatory infiltrate has been noted in

the wall of femoral and popliteal aneurysms, similar to aortic aneurysms.9 The exact role of this

inflammatory process, with potential release of reactive oxygen species and matrix metalloproteinases,

is unknown. Apoptosis of smooth muscle cells may also play a role in the formation of aneurysms by

limiting the ability of the arterial wall to respond to the degenerative process.10 These factors, however,

do not explain the male predilection for femoral and popliteal aneurysm formation. X-linked genetic

abnormalities for aneurysm formation in popliteal artery aneurysms have not been noted in humans.

Clinical Manifestations

Femoral and popliteal aneurysms are often asymptomatic, being detected on routine physical

examination by a bounding, expansile pulse. Both femoral and popliteal artery aneurysms, however,

may be accompanied by symptoms of local fullness, pain caused by pressure on the adjacent nerve, limb

edema, and venous distention or thrombosis caused by compression of the adjacent vein. Patients may

also present with lower extremity ischemia with intermittent claudication, rest pain, or gangrene

secondary to complications of a femoral or popliteal aneurysm including thrombosis or distal

embolization. Because the natural history and complication rate in femoral and popliteal aneurysms

differ, they are considered separately here.

FEMORAL ARTERY ANEURYSMS

2 Femoral artery aneurysms are the most common peripheral aneurysm if both true and false aneurysms

are considered together, with the vast majority being false aneurysms. Their clinical importance rests in

the fact that they are limb-threatening lesions and can jeopardize the viability of the leg if thrombosis,

embolization, or rupture occurs. The vast majority of true aneurysms are degenerative lesions

commonly called atherosclerotic aneurysms, whereas false aneurysms include anastomotic, traumatic, and

mycotic lesions. Rarely, femoral aneurysms develop secondary to connective tissue disorders. The

femoral region is the most common site for both anastomotic aneurysms and mycotic aneurysms

associated with trauma; so the presentation and surgical repair of these lesions are discussed.

Degenerative (Atherosclerotic) Aneurysms

Incidence

The exact incidence of degenerative (atherosclerotic) common femoral artery aneurysms in the general

population remains undefined. They are found in 6.8% of all patients with abdominal aortic aneurysms,

and 85% of patients with femoral artery aneurysms have abdominal aortic aneurysms.2,6

Pattern of Disease

Femoral aneurysms most frequently affect the common femoral artery. They may be classified as type I,

those limited to the common femoral artery, or type II, those involving the orifice of the profunda

femoris artery.11 Type I and type II aneurysms occur with nearly equal frequency. This classification

becomes important in reference to vascular reconstructive procedures, with type II aneurysms requiring

more complex reconstructions to ensure continued patency of both the superficial and profunda femoris

arteries. Isolated lesions of the profunda femoris artery are rare (2% of femoral artery aneurysms), and

are prone to rupture because they are difficult to diagnose at the asymptomatic stage. Isolated

superficial femoral artery aneurysms are also uncommon, but one-third of patients present with rupture

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and one-quarter with thrombosis.12

Femoral artery aneurysms can be limb-threatening lesions and are frequently associated with limbthreatening popliteal aneurysms and life-threatening abdominal aortic aneurysms. Multiple aneurysms

are common in patients with femoral artery aneurysms. In a series of 100 patients with degenerative

femoral artery aneurysms seen at a single institution, 72% of patients had bilateral femoral artery

aneurysms.6 In addition, aortoiliac aneurysms were detected in 85% of patients, thoracic aortic

aneurysms in 6%, and popliteal aneurysms in 44%, of which 55% were bilateral.

Clinical Manifestations

The typical patient with a degenerative femoral artery aneurysm is a male in his sixties or seventies

with the usual risk factors for atherosclerosis. Of these patients, 86% are cigarette smokers, 36% have

hypertension, and 14% have diabetes mellitus.6 Associated cardiovascular disease is common, with

clinical manifestations of coronary artery disease and cerebrovascular disease present in 34% and 7%,

respectively.

The clinical manifestations of femoral artery aneurysms cover the spectrum from asymptomatic to

severe ischemia of the lower extremity. Although 40% of patients are asymptomatic at the time of

diagnosis, the majority present with local symptoms or complaints of lower extremity ischemia.6 Local

pain or observation of a groin mass is the only complaint in 18% of patients. Lower extremity venous

disease is present in 8%, being attributable to venous obstruction by the femoral artery aneurysm in

4%; but venous obstruction is rarely the sole sign of an aneurysm. Lower extremity ischemic symptoms

of claudication, rest pain, or gangrene are present in 42% of patients and often lead to the diagnosis of

the femoral artery aneurysm.

As with aneurysms in other locations, femoral artery aneurysms may be complicated by embolization,

thrombosis, or rarely rupture. Peripheral embolization may be identified incidentally on angiography or

produce signs as mild as spotty discoloration of the toes to as severe as peripheral gangrene. Although

embolization is reported in about 10% of aneurysms, the femoral artery aneurysm is not necessarily the

source of these emboli because many patients have a concomitant popliteal aneurysm.6 In larger clinical

series, 1% to 16% of patients with degenerative femoral artery aneurysms present with an acute

thrombosis, whereas 1% to 16% have a chronically thrombosed lesion.6,10 Rupture is reported in 1% to

14% of aneurysms.6,11

Natural History

The natural history of degenerative femoral artery aneurysms is poorly defined. Most publications have

reviewed aneurysms that were treated surgically. A small asymptomatic femoral artery aneurysm does

not appear to pose the same threat to the limb as does a popliteal artery aneurysm. In a series of 236

patients with atherosclerotic femoral artery aneurysms, serious limb-threatening complications were

documented in only 3% of the 236 aneurysms.7

Diagnosis

In most cases the diagnosis of femoral artery aneurysm is suspected by the finding of a pulsatile groin

mass on routine physical examination or during evaluation for vascular disease. If the femoral artery

aneurysm is small or thrombosed, detection on physical examination may be difficult. Although a

radiograph of the region may occasionally demonstrate the calcified rim of the aneurysm, only

ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI) can reliably

establish the diagnosis of the femoral aneurysm. In addition, these modalities are useful in accurately

defining the size of the lesion and evaluating associated aneurysmal disease in the distal aorta and

popliteal regions. These findings are particularly important because life-threatening abdominal aortic

aneurysms are missed on physical examination in 50% of patients with multiple aneurysms.13 The

diagnostic accuracy of arteriography is limited because it demonstrates only the residual lumen and an

aneurysm filled with smooth mural thrombus may be missed, but the definition of the vascular anatomy

of the lower extremity provided by angiography is helpful in planning the appropriate operative

procedure (Fig. 97-1).

Treatment

Operative treatment of femoral aneurysms is indicated for those causing local symptoms and presenting

with limb-threatening complications. Asymptomatic aneurysms greater than 3.5 cm in diameter should

also be repaired unless the patient is a prohibitive risk for operative intervention. In patients with small,

asymptomatic aneurysms, observation may be appropriate, particularly in a patient with multiple

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medical problems who would be at high risk for surgery. When nonoperative management is selected,

the size of the aneurysm should be documented by ultrasonography. The patient should be followed at

regular intervals with ultrasound scans and careful examination for occult complications. Operative

treatment should be undertaken without undue delay if the femoral aneurysm enlarges, produces

symptoms, or is complicated by embolization, thrombosis, or rupture.

Figure 97-1. Arteriogram demonstrating bilateral femoral artery aneurysms that extend into the superficial femoral arteries. Unlike

many patients with femoral artery aneurysms, this patient did not have an associated aortic aneurysm or popliteal aneurysms.

Surgical Strategy. The operative approach is individualized based on associated aneurysmal disease. In

patients with multiple asymptomatic aneurysms, treatment is staged. The life-threatening aortic lesions

are treated before limb-threatening femoropopliteal lesions. Femoral artery aneurysms are addressed

after popliteal lesions unless the femoral aneurysm is repaired in combination with treatment of the

aortic or popliteal aneurysm. If an aortofemoral bypass is necessary, the femoral aneurysm should be

treated at the same time, to avoid later anastomotic aneurysm formation. The graft limb can be

anastomosed into an interposition graft that has replaced the femoral aneurysm. Similarly, if a stent

graft is placed for treatment of an abdominal aortic aneurysm in a patient with femoral artery

aneurysms, the aneurysm should be repaired with an interposition graft. In patients with severe lower

extremity ischemia, the femoral aneurysm is treated with an interposition graft, from which the

proximal anastomosis of the required femoropopliteal or femorotibial bypass is based.

Technique. The operative procedure for treatment of an isolated femoral artery aneurysm is

determined by aneurysmal involvement of the superficial and deep femoral arteries as well as by the

existence of lower extremity occlusive disease. The femoral artery aneurysm is usually approached

through a longitudinal groin incision. When addressing an unusually large aneurysm or a ruptured

aneurysm, however, initial proximal control of the external iliac artery through a retroperitoneal

approach is advisable. After proximal and distal arterial control is obtained, the aneurysm sac is opened

and the atheromatous debris removed. Small aneurysms may be excised, but routine excision of large

aneurysms is not recommended as these lesions can often be adherent to the adjacent vein and nerve.

For type I aneurysms, the preferred treatment is reconstruction with an interposition graft of Dacron or

expanded polytetrafluoroethylene with the proximal anastomosis at the distal external iliac artery or

proximal common femoral artery and the distal anastomosis at the femoral bifurcation.

For type II aneurysms with patent superficial and profunda femoris arteries, an interposition graft to

the profunda femoris artery with reimplantation of the superficial femoral artery is one standard

configuration. If the superficial femoral artery is chronically occluded and the patient has minimal

symptoms, an interposition graft to the profunda femoris artery alone is sufficient. If the patient has

severe lower extremity ischemia, this is typically followed by a standard distal reconstruction. If recent

emboli or in situ thrombosis have occluded the outflow tract, percutaneous mechanical

thromboembolectomy or catheter-directed thrombolytic therapy is useful before open arterial

reconstruction is undertaken.

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